Single-wedge wrenches

ABSTRACT

Disclosed is a single wedge wrench including two jaws, one of which has a zigzag gripping surface. The wrench further includes a wedge having a zigzag gripping surface. The wedge is mounted on an inner surface of the other one of the two jaws by means of a joint member, being slidable along the inner surface. The wrench disclosed can be used for bolts or nuts with various types and sizes, and an operation can be performed as long as a handle of the wrench is returned. The wrench can be manufactured with a simple process in a production line.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a hand tool, and more particularly to awrench having a jaw with a wedge.

2. Description of the Prior Art

There have been two kinds of wrenches in the art. One is an adjustablewrench and the other is a solid wrench. The wrench in the art comprisesa handle and a jaw. Gripping surfaces of the jaw are typically flat andface each other in parallel. Such conventional wrenches have thefollowing disadvantages in gripping and rotating an object such as apipe or a nut: (1) The gripping surfaces of the jaw are liable to slipalong a surface of the object; (2) When the wrench works in a limitedspace, the wrench must be adjusted to reengage the object frequently,which decreases the efficiency; and (3) The edge of the object is likelyto be damaged by a force directly applied thereto by the wrench.

In order to solve the problems of the gripping force of the conventionalwrench as mentioned above, a wedge-type wrench is disclosed by ChineseUtility Model No. 9210556.7. The wrench has two jaws, each having agripping surface. A sliding hole is provided at the each grippingsurface. A cylindrical wedge connected to a spring is disposed withinthe sliding hole. Two teeth working surfaces of the wedges are disposedopposite each other. When used to turn a nut, the two wedges can engagethe nut tightly to increase the friction and enhance the gripping force.The wrench can be adjusted to a proper position by simply turning itselfto make each wedge sliding within the respective sliding hole. Thus, thewrench can successively work without a repeated operation of releasingand reengaging the nut, thereby improving the working efficiency.

However, such a wrench has some drawbacks. (1) It cannot be used for asmall size object, because when the front ends of the two grippingsurfaces, each configured in an arc shape, contact each other, there isa gap between the rear ends thereof. (2) Since the wedge is directlyfixed in the sliding hole by a locating pin, the pin is easily damagedby a force the object exerts on the wedge during the operation. (3) Asthe wedge is of a cylindrical configuration, when the thickness of anobject is less than half of that of the wedge, the wedge will not firmlyclamp the object due to an uneven gripping force. (4) The production ofthe wrench requires a complex process. Two sliding holes, of which thecenterline is perpendicular to each other, are to be provided in thejaws to receive the wedges and springs.

BRIEF SUMMARY OF THE INVENTION

To overcome the shortcomings in the prior art as described above, thepresent invention provides a single-wedge wrench, which does not need tofrequently adjust the position of disengaging and reengaging an objectsuch as a nut, can apply a relatively larger torque of rotation to theobject, and is of a simple manufacturing process.

According to the invention, there is provided a single wedge wrenchcomprising two jaws, one of which has a zigzag gripping surface,characterized in that the wrench further comprises a wedge having azigzag gripping surface, which is mounted through a joint member on aninner surface of the other jaw of the two jaws, and is slidable alongthe inner surface.

According to an embodiment of the present invention, a guiding rail isconfigured in either the jaw or the wedge. A groove is formed in theguiding rail, and a spring is positioned at a bottom portion of thegroove along a longitudinal direction. The other of either the jaw orthe wedge is provided with a guiding slot corresponding to the guidingrail and a blind hole communicating with the guiding slot. The jointmember is an L-shaped member, of which a section is placed in the grooveof the wedge and connected to the spring, and another section is locatedwithin the blind hole of the jaw. A limitation element is provided inthe blind hole so as to confine the movement of the joint member.

According to the present invention, the jaw on which the wedge ismounted can be either an adjustable jaw or a stationary jaw. Inaddition, an angle ranging from 10 degrees to 70 degrees is formedbetween the inner surface of the jaw on which the wedge is mounted andthe gripping surface of the other jaw.

According to the invention, by providing a wedge slidable along thegripping surfaces of one of the jaws, a gap or space between twogripping surfaces can be adjusted so that the wrench can turn an objectwithout repeatedly disengaging and reengaging the object. Meanwhile,when a turning force is applied to the object, a counterforce generatedfrom the object to the wedge can make the wedge positioned at the jaw,which tightens or loosens the object in cooperation with the other jaw.The wrench of the invention provides the following advantages:

-   -   (1) The wrench of the present invention can be used for bolts or        nuts of various types and sizes. The wedge can tightly engage a        bolt or nut during operation. When the wrench needs to be        adjusted to a proper position during operation, it can be        reached by simply returning a handle of the wrench without        loosing the bolt or nut, whereupon the bolt or nut can be        clamped again. Furthermore, the invention realizes a surface        contact of the wrench with the bolt or nut instead of a line        contact in the prior art, which prevents the bolt or nut from        being damaged.    -   (2) A relatively large torque can be applied by the jaw        according to the invention so that the operation can be        performed more conveniently. Furthermore, when a position of the        wedge relative to the sliding hole changes upon a change of the        size of the object, the turning force can be transferred through        the wedge no matter what position it is, thereby preventing the        wedge from being damaged.    -   (3) The wrench of the present invention can be manufactured with        a simple process in a production line.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing the structure of an adjustable wrenchaccording to one embodiment of the present invention;

FIG. 2 is a schematic view taken from the direction of A shown in FIG.1;

FIG. 3 is a top view of an adjustable jaw 2 shown in FIG. 2;

FIG. 4 is a schematic sectional view taken from the direction of C shownin FIG. 3;

FIG. 5 is a schematic view showing the structure of a wedge 3 shown inFIG. 2;

FIG. 6 is a schematic view taken from the direction of B shown in FIG.5;

FIG. 7 is a schematic view of an L-shaped joint member 5 shown in FIG.1;

FIG. 8 is a schematic view taken from the direction of D shown in FIG.7;

FIG. 9 is a schematic view of another embodiment according to thepresent invention;

FIG. 10 is a schematic view taken from the direction of E shown in FIG.9;

FIG. 11 is a top plan view of the adjustable jaw 2 shown in FIG. 10;

FIG. 12 is a schematic view of a wedge 3 shown in FIG. 10;

FIG. 13 is a schematic view viewed along the direction of F shown inFIG. 12;

FIG. 14 is a schematic view of another embodiment according to thepresent invention;

FIG. 15 is a partial sectional view of an adjustable jaw shown in FIG.14;

FIG. 16A is a front view of a joint member shown in FIG. 14, and FIG.16B is a sectional view taken from the direction of B-B shown in FIG.16A;

FIGS. 17A and 17B are a schematic front view and a side view of a plateshown in FIG. 14, respectively; and

FIGS. 18A-18C are a side view, a schematic view taken from the directionof B, and a schematic view taken from the direction of C, respectively,of a wedge in FIG. 14.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the drawings, the preferred embodiments of the presentinvention will be further described as follows.

FIGS. 1 to 8 show a wrench according to a first preferred embodiment ofthe present invention. As shown in FIG. 1, a head portion of the wrenchof the preferred embodiment has a stationary jaw 1 and an adjustable jaw2. A zigzag gripping surface 11 is provided at the stationary jaw 1.Referring to FIG. 3 and FIG. 4 also, a guiding slot 22 and a blind hole23 communicated with the guiding slot 22 are provided at an innersurface 21 of the adjustable jaw 2 opposite to the stationary jaw 1.

As shown in FIG. 2, FIG. 5 and FIG. 6, the wrench of the first preferredembodiment of the present invention further comprises a wedge 3, whichis mounted on the adjustable jaw 2, provides a zigzag gripping surface31. A guiding rail 32 is configured at a surface of the wedge 3, whichmatches the inner surface 21 of the adjustable jaw 2. The guiding rail32 matches the guiding slot 22 of the adjustable jaw 2, and can slidewithin the guiding slot 22.

As shown in FIG. 1 and FIG. 6, a groove 33 is provided in the guidingrail 32. An open portion 331 of the groove 33 is rectangular, while abottom portion 332 of the groove 33 is circular. The diameter of thebottom portion 332 of the groove 33 is larger than the width of the openportion 331 of the groove 33. A spring 4 is installed within the groove33 along the longitudinal direction of the bottom portion 332.

As shown in FIG. 1, FIG. 7 and FIG. 8, a section 51 of an L-shaped jointmember 5 is installed in the groove 33, and connected to the spring 4placed in the groove 33. Another section 52 of the L-shaped joint member5 is mounted in the blind hole 23 of the adjustable jaw 2. A thread (notshown) is provided at an open portion of the blind hole 23 so that abolt 6 can be screwed therein. The bolt 6 functions to limit themovement of the section 52 of the L-shaped joint member 5 in the blindhole 23. The bolt 6 can be substituted by other components. For example,a rivet can be embedded into the blind hole 23.

In operation, when the wrench grips and rotates an object, the wedge 3is slidable along the inner surface 21 of the adjustable jaw 2, andthereby continuously adjusts the position by itself to grip the object.When the wrench is needed to be turned back to reengage the object in alimited space, a handle of the wrench is rotated to a desired positionin the counterclockwise direction. Because the inner surface 21 of theadjustable jaw 2 is inclined at a sharp angle relative to the grippingsurface 11 of the stationary jaw 1, when the handle is rotated in theanticlockwise direction, the wedge 3 can slide along the inner surface21 of the adjustable jaw 2, and the distance “H” between the grippingsurface 11 of the stationary jaw 1 and the gripping surface of the wedge3 can be continuously adjusted without rotating the object. The objectcan then be clamped and rotated again by further rotating the handle inthe clockwise direction. Repeating this operation can tighten theobject.

Moreover, since the wrench of the present invention has the structure asdescribed above, the object can be held easily due to the zigzagconfiguration of the wedge 3 and the stationary jaw 1 without damagingthe edge of the object (bolt or nut). On the other hand, when the objectis tightened, the force applied to the wedge 3 can be delivered inparallel to the adjustable jaw 2 and the handle of the wrench, so thatthe wrench can have a relatively large torque without affecting thewedge itself. These are also the advantages of the present inventionover the prior art.

Furthermore, for the wrench of the present invention, because one of thegripping surfaces of the wrench is fixed, while the wedge is connectedto the jaw in a right angle, the problem of rotating distortion existingin the wrench disclosed by Chinese Utility Model Patent No. 9210556.7can be avoided, even if the thickness of the object is less than half ofthat of the wedge.

FIGS. 9 to 13 show another preferred embodiment of the presentinvention. In this preferred embodiment, an alternative matchingstructure between the adjustable jaw 2 and the wedge 3 is configured toachieve the purpose that the wedge 3 can slide along the adjustable jaw2.

As shown from FIGS. 9 to 13, a zigzag gripping surface 31 is formed onthe wedge 3. A guiding slot 34 and a blind hole 35 communicated with theguiding slot 34 are formed in the surface of the wedge 3 which matchesthe inner surface 21 of the adjustable jaw 2. A guiding rail 24 and agroove 25 are formed in the inner surface 21 of the adjustable jaw 2. Anopen portion 251 of the groove 25 is rectangular and a bottom portion252 of the groove 25 is circular. The diameter of the bottom portion 252is larger than the width of the open portion 251 of the groove 25. Aspring 4 is disposed within the groove 25 along the longitudinaldirection of the bottom portion 252.

Referring to FIG. 9 in connection with FIG. 7 and FIG. 8, the section 51of the L-shaped joint member 5 is installed in the groove 25, andconnects the spring 4 placed in the groove 25. The other section 52 ofthe L-shaped joint member 5 is mounted in the blind hole 35 of theadjustable jaw 2. A thread (not shown) is provided at an open portion ofthe blind hole 35, so that the bolt 6 can be screwed into the blindhole. The bolt 6 limits the movement of the side section 52 of theL-shaped joint member 5 in the blind hole 35. The bolt 6 can besubstituted by a rivet or the like.

The wrench having the structure as mentioned above can realize the samefunctions as the first preferred embodiment.

FIGS. 14 to 18 show a further embodiment of the present invention.

As shown in FIG. 14, in the present embodiment, a fixed joint member 8is provided between the wedge 3 and the adjustable jaw 2. As shown inFIG. 15, two screw holes 26 and 26′ are formed at the inner surface 21of the adjustable jaw 2 (perpendicular to the inner surface 21). Asshown in FIG. 16A and FIG. 16B, two apertures 81 and 81′ each having atrapeziform cross-section are formed in the fixed joint member 8corresponding to the screw holes 26 and 26′. The fixed joint member 8can be secured on the inner surface 21 by two bolts with their headscorresponding to that of the apertures 81 and 81′. An L-shaped groove 82is formed at one end portion of the joint member. A plate 9 is installedin the groove 82.

As shown in FIGS. 16A, 16B, 17A and 17B, the shape of the plate 9 andthat of the groove 82 are configured to match each other. An upperportion 91 of the plate 9 is embedded into an upper portion 821 of thegroove 82, and a lower portion 92 of the plate 9 is embedded into alower portion 822 of the groove 82.

The structure of the wedge 3 in this embodiment is shown in FIGS. 18A to18C. An inverted trapeziform sliding slot 36 is formed (as shown in FIG.18B and FIG. 18C) at a mounting surface of the wedge 3. The sliding slot36 and the fixed joint member 8 are configured to match each other, sothat the fixed joint member 8 can be embedded into the sliding slot 36,and the sliding slot 36 can slide along the fixed joint member 8. Arecess 37 is formed at the bottom of the sliding slot 36, and the spring4 is placed in the recess 37. The length of the spring 4 isapproximately equal to that of the recess 37.

Firstly, to mount the wedge 3 onto the adjustable jaw 2, the plate 9 isplaced into the L-shaped groove 82 of the fixed joint member 8. At thistime, the angle between the upper portion 91 and the lower portion 92 ofthe plate 9 is larger (as shown in FIG. 17B), so that the insertion ofthe fixed joint member 8 into the recess 37 of the wedge 3 is nothindered. Then, the joint member 8 is fastened onto the inner surface 21of the adjustable jaw 2 by means of two bolts (not shown). Next, one end361 of the sliding slot 36 of the wedge 3 is aligned with the jointmember 8 and then the sliding slot 36 slides along the joint member 8 sothat the joint member 8 is embedded into the sliding slot 36. The spring4 is then put into the recess 37. Finally, as shown in FIG. 14, theupper portion 91 of the plate 9 is pressed to cover the sliding slot 36and the recess 37 of the wedge 3. In this way, the assembly of thewrench with a wedge according to this embodiment of the presentinvention is implemented.

In the embodiments mentioned above, the inner surface 21 of theadjustable jaw 2 and the gripping surface of the stationary jaw 1 canform an angle ranged from 10 degrees to 70 degrees.

Although the present invention has been explained in relation to theembodiments that a wedge 3 is mounted on an adjustable jaw 2 of anadjustable wrench, it is obvious to those skilled in the art that thisinvention can be applied in a solid wrench.

1-10. (canceled)
 11. A single wedge wrench, comprising: a handle; and ahead portion connected to the handle, comprising a stationary jaw havinga zigzag gripping surface; an adjustable jaw having an inner surfaceopposite the zigzag gripping surface; a wedge slidably connected to theadjustable jaw, the wedge having a guiding rail with a groove along alongitudinal direction of a mounting surface relative to the innersurface; a spring positioned within the groove at a bottom portionthereof, the spring being connected to the adjustable jaw; and a guidingslot disposed at the inner surface corresponding to the guiding rail sothat the wedge can slidably move along the adjustable jaw.
 12. Thewrench of claim 11 further comprising a joint member having a firstsection disposed in the groove and connected to the spring, and a secondsection located in a blind hole communicated with the guiding slotconfigured at the inner surface of the adjustable jaw.
 13. The wrench ofclaim 12, wherein a limitation element is provided at an open portion ofthe blind hole to confine the movement of the joint member.
 14. Thewrench of claim 13, wherein the limitation element is a bolt, the boltmatching a thread provided at the open portion of the blind hole. 15.The wrench of claim 13, wherein the limitation element is a rivet.
 16. Asingle wedge wrench, comprising: a handle; and a head portion connectedto the handle, comprising a stationary jaw, having a zigzag grippingsurface; an adjustable jaw having an inner surface opposite the zigzaggripping surface and a guiding rail having a groove along a longitudinaldirection of the inner surface; a spring positioned within a bottomportion of the groove, the spring being connected to the adjustable jaw;a wedge slidably connected to the adjustable jaw having a mountingsurface relative to the inner surface; and a guiding slot disposed atthe mounting surface corresponding to the guiding rail so that the wedgecan slidably move along the adjustable jaw.
 17. The wrench of claim 16further comprising a joint member having a first section disposed in thegroove and connected to the spring, and a second section located in ablind hole communicated with the guiding slot configured at the mountingsurface of the wedge.
 18. The wrench of claim 17, wherein a limitationelement is provided at an open portion of the blind hole to confine themovement of the joint member.
 19. The wrench of claim 18, wherein thelimitation element is a bolt, the bolt matching a thread provided at theopen portion of the blind hole.
 20. The wrench of claim 18, wherein thelimitation element is a rivet.
 21. A single wedge wrench, comprising: ahandle; and a head portion connected to the handle, comprising astationary jaw, having a zigzag gripping surface; an adjustable jawhaving an inner surface opposite the zigzag gripping surface; and awedge having a gripping surface, the wedge being slidably connected tothe inner surface of the adjustable jaw through a joint member fixed tothe inner surface, wherein the wedge has a sliding slot to receive thejoint member so that the wedge can slidably move along the adjustablejaw.
 22. The wrench of claim 21 wherein the sliding slot has a recess ata bottom of the wedge, and a spring is disposed in the recess to connectthe joint member,
 23. The wrench of claim 22 wherein a plate is providedto close one end of the sliding slot and one end of the recess.
 24. Thewrench of claim 21, wherein the joint member is configured in the shapeof an inverted trapeziform, and the sliding slot has such a shape thatthe joint member can slidably move therein.
 25. The wrench of claim 21,wherein the joint member is affixed to the inner surface by two screwbolts inserted into two screw holes at the inner surface and twoapertures corresponding to the screw holes respectively at the jointmember.
 26. The wrench of claim 24, wherein the joint member is affixedto the inner surface by two screw bolts inserted into two screw holes atthe inner surface and two apertures corresponding to the screw holesrespectively at the joint member.
 27. The wrench of claim 23, wherein anL-shaped groove is formed at one end portion of the fixed joint memberhaving an upper portion and a lower portion, and the plate comprises anupper section embedded into the upper portion of the L-shaped groove anda lower section embedded into a lower portion of the L-shaped groove.28. The wrench of claim 24, wherein an L-shaped groove is formed at oneend portion of the fixed joint member having an upper portion and alower portion, and the plate comprises an upper section embedded intothe upper portion of the L-shaped groove and a lower section embeddedinto a lower portion of the L-shaped groove.
 29. The wrench of claim 25,wherein an L-shaped groove is formed at one end portion of the fixedjoint member having an upper portion and a lower portion and the platecomprises an upper section embedded into the upper portion of theL-shaped groove, and a lower section embedded into a lower portion ofthe L-shaped groove.
 30. The wrench of claim 21, wherein an anglebetween the inner surface and the gripping surface ranges from 10degrees to 70 degrees.